1. Field of the Invention
The subject invention relates to a collapsible steering column assembly, and more specifically to an energy absorption device for the collapsible steering column assembly.
2. Description of the Prior Art
Currently, many steering column assemblies are equipped with kinetic energy absorption devices to reduce a likelihood of injury resulting from a vehicular accident. There are several different types and variations of these kinetic energy absorption devices, typically involving the deformation of a plastically deformable metal. An example of such a kinetic energy absorption device is disclosed in U.S. Pat. No. 6,523,432 to Yamamoto (the '432 patent).
The '432 patent discloses a collapsible steering column assembly comprising a steering shaft supported within a column jacket and extending along a longitudinal axis. A bracket is mounted to the column jacket, and attaches the steering column assembly to a vehicle. The bracket defines a bolt hole extending transverse to the longitudinal axis, and a slot extending from the bolt hole parallel the longitudinal axis. The slot includes a pre-determined width less than a diameter of the bolt hole. A bolt having a shank within a collar is disposed within the bolt hole so as to deform edges of the slot as a result of the steering column collapsing along the longitudinal axis during a collision event. The amount of energy absorbed by the energy absorption device disclosed in the '432 patent depends upon material properties and physical dimensions of the components of the energy absorption device, and cannot be altered once the components of the energy absorption device have been installed on the steering column.